Rejoy.se is the only verified reseller of those so far, and only within europe, they've yet to have an official USA release, which is sad cause they look MUCH better than others... And if they do idneed take 4 microSDHC carts in them like it says, 32GB would be QUITE nice. The pictures show that it sticks out the side a bit, but that's not a large problem.

This is the first I've heard of the multiple version, but the common single adapters don't have a reputation for speed. Also, it appears that the poster in the linked thread tested the MicroSD without the MSPD adapter.